Physics Lectures Practice Session Testing Mode Video No. 18

Testing Mode Video No. 18 Module # 21 Scalars & Vectors Scalars Physical quantities used in various fields of science are either scalars or vectors. A scalar is a physical quantity which is completely described by a number with proper units. Some of the well-known examples of scalars (or scalar quantities) are mass, distance, temperature, energy, time, volume, density, speed, work, power, wave length, atmospheric pressure and electrical charge as they require only magnitude with proper units for their complete description. The scalars are added, subtracted and multiplied by the usual arithmetical rules. Vectors Physical quantities used in various fields of science are either scalars or vectors. A physical quantity which requires magnitude with proper units as well as direction is called a vector. Suppose, we are told that a person moves a distance of 10 m from the point O, then, he may be located anywhere on the circumference of a circle of radius 10 m with its centre at O. Thi